This invention relates generally to table and floor lamps, and more particularly to a lamp whose stand provides a stable and properly-oriented support for a lampshade.
The typical floor or table lamp consists of a stand in the form of a rod or pole ahchored on a weighted base and carrying a socket for a light bulb, the pole also supporting a harp to which a lampshade is attachable.
The conventional harp is composed of a wire hoop defined by a pair of opposed arms which extend upwardly from a ring attached to the pole of the lampstand below the bulb socket. Clamped to the top of the harp is a fixture from which a short threaded stud extends. The typical lampshade includes a spider whose arms radiate from a central collar receivable on the harp stud and secured thereto by a nut.
The stability of the harp of the hoop type depends on the stiffness of the wire from which it is formed. In practice, it is usually possible, particularly with a large shade, to produce a sufficient moment about the point of attachment, to bend and deform the harp and thereby tilt the shade. Moreover, while the fixture on top of the harp is clamped thereto, it has a tendency to turn on the hoop when a force is applied to the shade in a direction producing a torque, the spider acting as a lever providing a mechanical advantage.
As a consequence, one often finds that with a conventional floor or table lamp which from time to time is handled to change its room placement, that the lampshade assumes an improper orientation on the stand. In trying to correct this condition, the homeowner usually manipulates the wire spider in the hope of straightening out the shade position. More ofter than not, this simply worsens the situation.
The problem of lampshade orientation with a cnventional lampstand is even more vexatious when the shade is in the form of a Chinese or Japanese lantern (hereinafter referred to as an oriental lantern). One lantern of this type is composed of a translucent thin paper or fabric shell of spheroidal form having reinforcing bamboo ribs in spiral form embedded therein, the shell being provided with polar openings bordered by circular ribs.
When oriental lanterns of different size are suspended from a conventional harp with the upper polar rib attached to the harp fixture, then one not only is faced with the problem of an off-center shade orientation as a result of an imperfect harp position but also with the problem of centering the bulb within the lantern as well as the problem of maintaining the collapsible lantern in a fully-expanded state. With a conventional lampstand arrangement, one cannot subject the lantern shell to tension to fully expand its form. While it is known to install a wire stretcher within a lantern to tension the shell, such stretchers are not usable when the lantern is mounted on a lampstand harp.